Math Skill: Using Parentheses
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View Lesson | View Sample Problems | Do Worksheet
Instructional videos are displayed with permission from Khan Academy.
Using Parentheses
When evaluating expressions that have parentheses, you always evaluate what is in the parentheses first.
When you don't evaluate what's in the parentheses first, you will get the wrong answer.
Let's take 3 × (8 - 5) as an example.
Right:
3 × (8 - 5) = 3 × 3 = 9
Evaluate what is in the parentheses first.Wrong:
3 × (8 - 5) = 3 × 8 - 5 = 24 - 5 = 19
Ignoring parentheses gets the wrong answer.
If there is a pair of parentheses within a pair of parentheses, then evaluate what is in the inner pair of parentheses first.
Example:
(10 + (6 ÷ 2)) + (4 × 3)
(10 + (6 ÷ 2)) + (4 × 3) = Evaluate the inner parentheses first (10 + 3) + (4 × 3) = (10 + 3) + (4 × 3) = Evalute the remaining parentheses 13 + 12 = 25
